Snail mail and smail (from snail + mail)—named after the snail with its slow speed—refers to letters and missives carried by conventional postal delivery services. The phrase refers to the lag-time between dispatch of a letter and its receipt, versus the virtually instantaneous dispatch and delivery of its electronic equivalent, e-mail.
It is also known, more neutrally, as paper mail, postal mail, land mail, or simply mail and post. An earlier term of the same type is surface mail, coined retrospectively after the development of airmail. This happened between the 1970s to 1990s.
Snail mail penfriends or penpals are those that communicate with one another through the postal system, rather than on the internet which has become the more common medium.
Some online groups also use paper mail through regular gift or craft hot topics. In some countries, services are available to print and deliver emails to those unable to receive email, like people with no computers or internet access.